Method for producing 1,1,2-trifluoroethane (HFC-143)

ABSTRACT

The present disclosure provides a method for producing HFC-143 that is not expensive, and that is more efficient than conventional methods. Specifically, the present disclosure provides a method for producing 1,1,2-trifluoroethane (HFC-143) that includes contacting at least one chlorine-containing compound selected from the group consisting of 1,1,2-trichloroethane (HCC-140), 1,2-dichloro-1-fluoroethane (HCFC-141), 1,1-dichloro-2-fluoroethane (HCFC-141a), (E,Z)-1,2-dichloroethylene (HCO-1130 (E,Z)), and (E,Z)-1-chloro-2-fluoroethylene (HCFO-1131 (E,Z)) with hydrogen fluoride to perform one or more fluorination reactions, thereby obtaining a reaction gas containing HFC-143, hydrogen chloride, and hydrogen fluoride.

TECHNICAL FIELD

The present disclosure relates to a method for producing1,1,2-trifluoroethane (HFC-143).

BACKGROUND ART

Fluoroethanes, such as 1,1,2-trifluoroethane (CHF₂CH₂F; “HFC-143”below), are known as a starting material for producing variousrefrigerants. For example, HFC-143 is known as a starting material forproducing 1,2-difluoroethylene (HFO-1132).

A variety of methods for producing a fluoroethane such as HFC-143 havebeen proposed. For example, PTL 1 proposes a technique to produceHFC-143 by performing a hydrogenation reaction ofchlorotrifluoroethylene (CTFE) in the presence of a hydrogenationcatalyst. PTL 2 also discloses a technique to produce2-chloro-1,1-difluoroethane (HCFC-142) from 1,1,2-trichloroethane(HCC-140), and discloses that a small amount of HFC-143 is mixed as aby-product.

CITATION LIST

Patent Literature

PTL 1: JPH01-287044A

PTL 2: WO2015/082812A

SUMMARY

A method for producing 1,1,2-trifluoroethane (HFC-143) comprisescontacting at least one chlorine-containing compound selected from thegroup consisting of 1,1,2-trichloroethane (HCC-140),1,2-dichloro-1-fluoroethane (HCFC-141), 1,1-dichloro-2-fluoroethane(HCFC-141a), (E,Z)-1,2-dichloroethylene (HCO-1130 (E,Z)), and(E,Z)-1-chloro-2-fluoroethylene (HCFO-1131 (E,Z)) with hydrogen fluorideto perform one or more fluorination reactions, thereby obtaining areaction gas containing HFC-143, hydrogen chloride, and hydrogenfluoride.

ADVANTAGEOUS EFFECTS

The method for producing HFC-143 according to the present disclosureproduces HFC-143 at low cost, and more efficiently than conventionalmethods.

DESCRIPTION OF EMBODIMENTS

A feature of the method for producing HFC-143 according to the presentdisclosure is that the method includes contacting at least onechlorine-containing compound selected from the group consisting of1,1,2-trichloroethane (HCC-140), 1,2-dichloro-1-fluoroethane (HCFC-141),1,1-dichloro-2-fluoroethane (HCFC-141a), (E,Z)-1,2-dichloroethylene(HCO-1130 (E,Z)), and (E,Z)-1-chloro-2-fluoroethylene (HCFO-1131 (E,Z))with hydrogen fluoride to perform one or more fluorination reactions,thereby obtaining a reaction gas containing HFC-143, hydrogen chloride,and hydrogen fluoride.

Due to such a feature, the method for producing HFC-143 according to thepresent disclosure can produce HFC-143 at low cost, and more efficientlythan conventional methods.

The production method according to the present disclosure uses as astarting material compound at least one chlorine-containing compoundselected from the group consisting of HCC-140, HCFC-141, HCFC-141a,HCO-1130 (E,Z), and HCFO-1131 (E,Z). “(E,Z)” indicates that a compoundto which “(E,Z)” is attached includes its E-form and/or Z-form. Thesechlorine-containing compounds, which are all available at lower pricesthan CTFE, can reduce the cost of producing HFC-143. Of thesechlorine-containing compounds, at least either HCC-140 or HCO-1130 (E,Z)is preferable from the standpoint of starting material cost.

A feature of the production method according to the present disclosureis that the method includes contacting the above-describedchlorine-containing compound with hydrogen fluoride to perform one ormore fluorination reactions, thereby obtaining a reaction gas containingHFC-143, hydrogen chloride, and hydrogen fluoride.

The one or more fluorination reactions performed with hydrogen fluoridemay be a gas-phase reaction or a liquid-phase reaction. The fluorinationreaction that is performed until HFC-143 is obtained may be onefluorination reaction or two or more fluorination reactions, dependingon the chlorine-containing compound for use.

In the case of a gas-phase reaction, it is sufficient if thechlorine-containing compound and the hydrogen fluoride both in their gasform come into contact with each other within the reaction temperaturerange described later. The chlorine-containing compound may be in liquidform when being supplied.

For example, a chlorine-containing compound in liquid foam at roomtemperature under ordinary pressure is vaporized with a vaporizer, andthen allowed to pass through a preheating region; and supplied to amixing region in which the chlorine-containing compound is brought intocontact with hydrogen fluoride, thereby performing a reaction in a gasphase. Alternatively, a chlorine-containing compound in liquid form maybe supplied to a reactor, and vaporized when the chlorine-containingcompound has reached a region within which the compound is reactive withthe hydrogen fluoride to cause a reaction.

The hydrogen fluoride for use is preferably anhydrous hydrogen fluoride,from the standpoint of suppressing the corrosion of the reactor or thedegradation of the catalyst.

The method for vaporizing a chlorine-containing compound in a reactionregion can be any method, and may be selected from a wide range of knownmethods. For example, the following method may be used. A reaction tubeis filled with a material that is excellent in heat conductance, has nocatalytic activity in a fluorination reaction, and is stable againsthydrogen fluoride, such as nickel beads and Hastelloy pieces. Thetemperature distribution inside the reaction tube is then made uniform,and the reaction tube is heated to a temperature equal to or higher thanthe vaporization temperature of the chlorine-containing compound. Thechlorine-containing compound in liquid form is supplied to the reactortube, and vaporized so as to transform into a gas phase.

The method for supplying hydrogen fluoride to a reactor can be anymethod. For example, hydrogen fluoride in a gas phase can be supplied toa reactor together with a chlorine-containing compound. The amount ofhydrogen fluoride to be supplied is the following: the molar ratio ofthe hydrogen fluoride to the chlorine-containing compound (1 mol) ispreferably 20 or more, more preferably 30 or more, and still morepreferably 40 or more (in particular, over 40). The upper limit of themolar ratio is, although not limited to, preferably about 60 from thestandpoint of energy cost and productivity.

A molar ratio within these ranges enables both the chlorine-containingcompound conversion and HFC-143 selectivity to be maintained within amore efficient (excellent) range than conventional methods. Inparticular, supplying 40 mol or more (in particular, over 40 mol) ofhydrogen fluoride per mol of a chlorine-containing compound cansignificantly increase the selectivity for HFC-143.

In the present specification, “conversion” refers to the proportion (mol%) of the total mol of the compounds other than the compounds describedabove contained in an outflow gas (i.e., a reaction gas) coming from theoutlet of the reactor relative to the mol of the chlorine-containingcompound supplied to the reactor.

In the present specification, “selectivity” refers to the proportion(mol %) of the mol of the target compound (HFC-143) contained in anoutflow gas (i.e., a reaction gas) coming from the outlet of the reactorrelative to the total mol of the compounds other than the compoundsdescribed above.

In a fluorination reaction in a gas phase, the chlorine-containingcompound as a starting material compound may be supplied to a reactor asis; or the chlorine-containing compound may be diluted with an inert gassuch as nitrogen, helium, or argon, and then supplied to the reactor.

A fluorination reaction in the presence of a catalyst in a gas phase canuse any known gas-phase fluorination catalyst selected from a wide rangeof such catalysts. Examples include oxides, hydroxides, halides, halogenoxides, and inorganic salts of chromium, aluminum, cobalt, manganese,nickel, or iron; and mixtures thereof. Of these, in order to increasethe conversion of the chlorine-containing compound, chromium-basedcatalysts such as CrO₂, Cr₂O₃, FeCl₃/C, Cr₂O₃/Al₂O₃, Cr₂O₃/AlF₃,Cr₂O₃/C, and CoCl₂/Cr₂O₃ are preferable for use. The chromiumoxide/aluminum oxide-based catalysts for use are preferably thosedisclosed in U.S. Pat. No. 5,155,082, specifically a chromiumoxide/aluminum oxide catalyst (e.g., Cr₂O₃/Al₂O₃); and those obtained bycombining a halide of cobalt, nickel, manganese, rhodium, or rutheniumwith such a chromium oxide/aluminum oxide catalyst. Specifically, in thecase of a gas-phase reaction, the catalyst is preferably at least partlya chromium-based catalyst.

The metallic catalyst for use may be a partly or entirely crystallizedcatalyst, or an amorphous catalyst. The crystallizability can besuitably selected. For example, chromium oxide with a variety ofparticle sizes is commercially available. To control the particle sizeand crystallizability, a metallic catalyst may be prepared byprecipitating chromium hydroxide from chromium nitrate and ammonia, andburning the precipitate. The catalyst for use may be a single catalyst,or a mixture of two or more catalysts. The carrier for use may be, forexample, a variety of activated carbon, magnesium oxide, zirconia oxide,or alumina. These catalysts may be subjected to fluorination treatmentusing, for example, anhydrous hydrogen fluoride or a fluorine-containingcompound before they are used in a fluorination reaction. In particular,these catalysts are preferably subjected to fluorination treatment usinganhydrous hydrogen fluoride.

The form of the reactor for use can be any form; the reactor for use canbe selected from a wide range of known reactors. For example, atube-form flow reactor filled with a catalyst can be used. In a reactionin the absence of a catalyst, the reactor for use can be, for example,an adiabatic reactor with a void-tower, or an adiabatic reactor filledwith a porous or non-porous metal or medium for increasing the degree ofmixture of the hydrogen fluoride and the starting material in their gasphase. Alternatively, the reactor for use is preferably, for example, amulti-tube reactor from which heat is removed by using a heat mediumand/or whose temperature distribution is made uniform.

In the use of a reactor with a void-tower, for example, the relationshipbetween the flow rate of a chlorine-containing compound and the innerdiameter of a reaction tube is preferably set such that the linearvelocity is high and the heat-transfer area is large, in order toimprove heat-transfer efficiency using a reaction tube with a smallinner diameter.

The reaction temperature in a gas-phase fluorination reaction as atemperature inside the reactor is preferably 150 to 600° C., morepreferably 200 to 500° C., and still more preferably 230 to 400° C.Setting the reaction temperature to 200° C. or more can improve theselectivity for a target product. A reaction temperature of 600° C. orless can reduce the risk such that carbides are formed by the reaction,and that these carbides adhere to and/or accumulate on the reaction tubewall or on the filler to gradually block the reactor. However, if such arisk is involved, carbides remaining in the reaction tube can be removedthrough combustion by entraining oxygen into the reaction system, or bytemporarily stopping the reaction to allow oxygen or air to circulate.

The reaction pressure in a gas-phase fluorination reaction can be anypressure under which a chlorine-containing compound and hydrogenfluoride can exist in their gas phase. The reaction pressure can be anordinary pressure, increased pressure, or decreased pressure. Forexample, the reaction can be performed under reduced pressure oratmospheric pressure (0 MPaG); the reaction can also be performed underincreased pressure, as long as the starting materials do not transforminto liquid. Typically, the reaction pressure is preferably within therange of 0 to 2 MPaG, and more preferably 0 to 1 MPaG.

The reaction time for the gas-phase fluorination reaction can be anytime. Typically, the contact time represented by W/Fo (the ratio of thecatalyst added W (g) to the total flow rate Fo (flow rate at 0° C. under0.0 MPaG: cc/sec) of the starting material gas that is allowed to flowin a reaction system) is about 0.1 to 100 g·sec/cc, and preferably about5 to 50 g·sec/cc. The total flow rate of the starting material gas inthis case refers to the sum of the total flow rate of thechlorine-containing compound and the hydrogen fluoride (startingmaterials), and the flow rate of inert gas, oxygen, or the like, whensuch an optional component is added.

The liquid-phase catalyst for use in performing a fluorination reactionin the presence of a catalyst in a liquid phase can be any catalyst, andcan be selected from a wide range of known liquid-phase fluorinationcatalysts. Specifically, the liquid-phase catalyst for use may be atleast one member selected from the group consisting of Lewis acid,transition metal halides, transition metal oxides, halides of the metalsof the group IVb, and halides of the metals of the group Vb.

More specifically, the liquid-phase catalyst for use may be at least onemember selected from the group consisting of antimony halides, tinhalides, tantalum halides, titanium halides, niobium halides, molybdenumhalides, iron halides, halogenated chromium fluoride, and oxidizedchromium fluoride.

More specifically, the liquid-phase catalyst for use is preferablySbCl₅, SbCl₃, SbF₅, SnCl₄, TaCl₅, TiCl₄, NbCl₅, MoCl₆, and FeCl₃; andthose prepared from a chloride salt and hydrogen fluoride, such asSbCl_((5-y))F_(y), SbCl_((3-y))F_(y), SnCl_((4-y))F_(y),TaCl_((5-y))F_(y), TiCl_((4-y))F_(y), NbCl_((5-y))F_(y),MoCl_((6-y))F_(y), and FeCl_((3-y))F_(y) (the lower limit of y is 0.1 ormore, and the upper limit of y is equal to or lower than the valence ofindividual elements). These catalysts can be used singly, or in acombination of two or more. Of these, catalysts that are at least partlyan antimony-based catalyst are preferable, and antimony pentachloride isparticularly preferable.

These catalysts can be easily renewed by a known technique when theyhave become inactive. A usable method for renewing such a catalyst isbringing chlorine into contact with the catalyst. For example, chlorinein an amount of about 0.15 to 25 g/hr may be added per 100 g of aliquid-phase fluorination catalyst in a liquid-phase reaction.

The reaction temperature in a liquid-phase fluorination reaction as atemperature inside a reaction system is preferably 50 to 200° C., andmore preferably 80 to 150° C. Setting the reaction temperature to 80° C.or more can increase the selectivity for a target product andproductivity. The pressure in a liquid-phase fluorination reaction ispreferably within the range of 0 to 2 MPaG, and more preferably 0 to 1MPaG as in a gas-phase reaction.

The reactor for use in both the gas-phase fluorination reaction and theliquid-phase fluorination reaction can be any reactor, and can beselected from a wide range of known reactors. Specifically, the reactorfor use is preferably one formed of a material that is resistant tocorrosive action by hydrogen fluoride, such as Hastelloy, Inconel,Monel, or Incoloy.

After a reaction gas containing HFC-143, hydrogen chloride, and hydrogenfluoride is obtained by the production method according to the presentdisclosure, HFC-143 can be obtained by using various known separationmethods. The hydrogen fluoride can be recycled in a fluorinationreaction. The obtained HFC-143 can be optionally subjected topurification treatment, and then used for various purposes. For example,1,2-difluoroethylene (HFO-1132) may be produced by subjecting HFC-143 toa dehydrofluorination reaction. From this perspective, the presentdisclosure also includes a disclosure related to a method for producing1,2-difluoroethylene (HFO-1132) that includes subjecting1,1,2-trifluoroethane (HFC-143) contained in the reaction gas obtainedby the above-described production method according to the presentdisclosure to a dehydrofluorination reaction. This method for producingHFO-1132 can also be described as “a method for producing1,2-difluoroethylene (HFO-1132) comprising performing the productionmethod according to the present disclosure, and subjecting1,1,2-trifluoroethane (HFC-143) contained in the obtained reaction gasto a dehydrofluorination reaction.”

Embodiments of the present disclosure have been described above.However, the present disclosure is not limited to these embodiments inany way. Various modifications may be made without departing from thespirit and principal concept of the present disclosure.

As described above, the present disclosure includes the following.

-   1. A method for producing 1,1,2-trifluoroethane (HFC-143), the    method comprising    -   contacting at least one chlorine-containing compound selected        from the group consisting of 1,1,2-trichloroethane (HCC-140),        1,2-dichloro-1-fluoroethane (HCFC-141),        1,1-dichloro-2-fluoroethane (HCFC-141a),        (E,Z)-1,2-dichloroethylene (HCO-1130 (E,Z)), and        (E,Z)-1-chloro-2-fluoroethylene (HCFO-1131 (E,Z)) with hydrogen        fluoride to perform one or more fluorination reactions, thereby        obtaining a reaction gas containing HFC-143, hydrogen chloride,        and hydrogen fluoride.-   2. The production method according to Item 1, wherein the one or    more fluorination reactions are performed under a pressure of 0 to 2    MPaG.-   3. The production method according to Item 1 or 2, wherein the one    or more fluorination reactions are performed in the presence of a    catalyst in a gas phase.-   4. The production method according to Item 3, wherein the one or    more fluorination reactions are performed at a temperature of 150 to    600° C.-   5. The production method according to Item 3 or 4, wherein the    contact time W/Fo between the at least one chlorine-containing    compound and the hydrogen fluoride is 0.1 to 100 g·sec/cc in the one    or more fluorination reactions.-   6. The production method according to any one of Items 1 to 5,    wherein the molar ratio of the hydrogen fluoride to the at least one    chlorine-containing compound in the one or more fluorination    reactions is 20 or more.-   7. The production method according to any one of Items 1 to 5,    wherein the molar ratio of the hydrogen fluoride to the at least one    chlorine-containing compound in the one or more fluorination    reactions is over 40.-   8. The production method according to any one of Items 3 to 7,    wherein the catalyst is at least partly a chromium-based catalyst.-   9. The production method according to Item 1 or 2, wherein the one    or more fluorination reactions are performed in the presence of a    catalyst in a liquid phase.-   10. The production method according to Item 9, wherein the catalyst    is at least partly an antimony-based catalyst.-   11. A method for producing 1,2-difluoroethylene (HFO-1132), the    method comprising subjecting 1,1,2-trifluoroethane (HFC-143)    contained in the reaction gas obtained by the production method of    any one of claims 1 to 10 to a dehydrofluorination reaction.

EXAMPLES

Embodiments of the present disclosure are described in more detail belowwith reference to Examples. However, the present disclosure is notlimited to the scope of the Examples.

Example 1

A chromium fluoride oxide catalyst was prepared in accordance with thefollowing procedure. First, chromium oxide represented by CrxOy wasprepared in accordance with the method disclosed in JPH05-146680A.Specifically, 10% ammonia water was added to 765 g of a 5.7% aqueouschromium nitrate solution; and the thus-formed precipitate was collectedby filtration, followed by washing and then drying in air at 120° C. for12 hours, thereby obtaining chromium hydroxide. This chromium hydroxidewas then famed into pellets with a diameter of 3.0 mm and a height of3.0 mm. The pellets were then burned in a nitrogen stream at 400° C. for2 hours, thereby obtaining chromium oxide. The obtained chromium oxidehad a specific surface area (according to the BET theory) of about 200m²/g. Subsequently, this chromium oxide was subjected to fluorinationtreatment to obtain a chromium fluoride oxide catalyst. Specifically,while a hydrogen fluoride-containing gas was allowed to flow intochromium oxide, the temperature was increased to 200 to 360° C.incrementally to heat the chromium oxide. After the temperature reached360° C., fluorination was performed using hydrogen fluoride for 2 hours,thereby obtaining a chromium fluoride oxide catalyst.

A tubular Hastelloy reactor with an inner diameter of 15 mm and a lengthof 1 m was then charged with 12 g of the obtained chromium fluorideoxide catalyst.

This reaction tube was maintained at 150° C. under atmospheric pressure(0.0 MPaG). Anhydrous hydrogen fluoride (HF) gas was supplied to thereactor at a flow rate of 118 mL/min (flow rate at 0° C. under 0.0MPaG), and the reactor was maintained for 1 hour. Thereafter, CHCl₂CH₂Cl(HCC-140) was supplied at a flow rate of 2.4 mL/min (gas flow rate at 0°C. under 0.0 MPaG). In this case, the molar ratio, HF:HCC-140, was 50:1,and the contact time W/Fo was 6 g·sec/cc.

After 1.5 hours from the start of the reaction, the conversion ofHCC-140 was 56.4%, and the selectivity for HFC-143 was 0.4%.

Example 2

HFC-143 was synthesized in the same manner as in Example 1, except thatthe reaction temperature was changed to 240° C.

After 2.5 hours from the start of the reaction, the conversion ofHCC-140 was 99.8%, and the selectivity for HFC-143 was 2.4%.

Example 3

HFC-143 was synthesized in the same manner as in Example 1, except thatthe reaction temperature was changed to 280° C.

After 2.5 hours from the start of the reaction, the conversion ofHCC-140 was 100%, and the selectivity for HFC-143 was 6.5%.

Example 4

HFC-143 was synthesized in the same manner as in Example 1, except thatthe reaction temperature was changed to 330° C.

After 1.5 hours from the start of the reaction, the conversion ofHCC-140 was 100%, and the selectivity for HFC-143 was 4.1%.

Example 5

HFC-143 was synthesized in the same manner as in Example 1, except thatanhydrous hydrogen fluoride (HF) gas was supplied to the reactor at aflow rate of 57.4 mL/min (flow rate at 0° C. under 0.0 MPaG), and thereaction temperature was changed to 200° C. In this case, the molarratio, HF:HCC-140, was 24.3:1, and the contact time W/Fo was 12g·sec/cc.

After 2 hours from the start of the reaction, the conversion of HCC-140was 98.3%, and the selectivity for HFC-143 was 0.1%.

Example 6

HFC-143 was synthesized in the same manner as in Example 5, except thatthe reaction temperature was changed to 240° C.

After 3 hours from the start of the reaction, the conversion of HCC-140was 100%, and the selectivity for HFC-143 was 1.9%.

Example 7

HFC-143 was synthesized in the same manner as in Example 5, except thatthe reaction temperature was changed to 280° C.

After 2 hours from the start of the reaction, the conversion of HCC-140was 100%, and the selectivity for HFC-143 was 2.7%.

Example 8

HFC-143 was synthesized in the same manner as in Example 1, except thatanhydrous hydrogen fluoride (HF) gas was supplied to the reactor at aflow rate of 35 mL/min (flow rate at 0° C. under 0.0 MPaG), and thereaction temperature was changed to 280° C. In this case, the molarratio, HF:HCC-140, was 15:1, and the contact time W/Fo was 19 g·sec/cc.

After 2 hours from the start of the reaction, the conversion of HCC-140was 100%, and the selectivity for HFC-143 was 1.4%.

The results of Example 8 indicate that because a low molar ratio led toa reduced yield of HFC-143, the yield of HFC-143 can be increased bysetting the molar ratio to 20 or more, preferably 40 or more (inparticular, over 40).

Example 9

HFC-143 was synthesized in the same manner as in Example 8, except thatthe reaction temperature was changed to 365° C.

After 2 hours from the start of the reaction, the conversion of HCC-140was 100%, and the selectivity for HFC-143 was 0.27%.

Example 10

A tubular Hastelloy reactor with an inner diameter of 15 mm and a lengthof 1 m was charged with 12 g of the chromium fluoride oxide catalystprepared in Example 1.

This reaction tube was maintained at 240° C. under atmospheric pressure(0.0 MPaG). Anhydrous hydrogen fluoride (HF) gas was supplied to thereactor at a flow rate of 63 mL/min (flow rate at 0° C. under 0.0 MPaG),and the reactor was maintained for 1 hour. Thereafter, CHClCHCl(HCO-1130) was supplied at a flow rate of 3 mL/min (gas flow rate at 0°C. under 0.0 MPaG). In this case, the molar ratio, HF:HCO-1130, was21:1, and the contact time W/Fo was 11 g·sec/cc.

After 19 hours from the start of the reaction, the conversion ofHCO-1130 was 29%, and the selectivity for HFC-143 was 6.8%.

Example 11

HFC-143 was synthesized in the same manner as in Example 10, except thatanhydrous hydrogen fluoride (HF) gas was supplied to the reactor at aflow rate of 61.9 mL/min (flow rate at 0° C. under 0.0 MPaG), andHCO-1130 was supplied to the reactor at a flow rate of 4.1 mL/min (gasflow rate at 0° C. under 0.0 MPaG). In this case, the molar ratio,HF:HCO-1130, was 15:1, and the contact time W/Fo was 11 g·sec/cc.

After 2 hours from the start of the reaction, the conversion of HCO-1130was 25.5%, and the selectivity for HFC-143 was 3.3%.

Example 12

HFC-143 was synthesized in the same manner as in Example 10, except thatanhydrous hydrogen fluoride (HF) gas was supplied to the reactor at aflow rate of 64.7 mL/min (flow rate at 0° C. under 0.0 MPaG), andHCO-1130 was supplied to the reactor at a flow rate of 1.3 mL/min (gasflow rate at 0° C. under 0.0 MPaG). In this case, the molar ratio,HF:HCO-1130, was 50:1, and the contact time W/Fo was 11 g·sec/cc.

After 2 hours from the start of the reaction, the conversion of HCO-1130was 63.5%, and the selectivity for HFC-143 was 14.6%.

A comparison between the results of Example 11 and the results ofExample 10 and Example 12 indicates that because a low molar ratio ledto a reduced yield of HFC-143, the yield of HFC-143 can be increased bysetting the molar ratio to 20 or more, preferably 40 or more (inparticular, over 40).

Example 13

HFC-143 was synthesized in the same manner as in Example 10, except thatanhydrous hydrogen fluoride (HF) gas was supplied to the reactor at aflow rate of 150 mL/min (flow rate at 0° C. under 0.0 MPaG), HCO-1130was supplied to the reactor at a flow rate of 3 mL/min (gas flow rate at0° C. under 0.0 MPaG), the reaction pressure was changed to 0.6 MPaG,and the reaction temperature was changed to 200° C. In this case, themolar ratio, HF:HCO-1130, was 50:1, and the contact time W/Fo was 4.7g·sec/cc.

After 2 hours from the start of the reaction, the conversion of HCO-1130was 40%, and the selectivity for HFC-143 was 5.9%.

Example 14

HFC-143 was synthesized in the same manner as in Example 13, except thatthe reaction pressure was changed to 0.0 MPaG.

After 2 hours from the start of the reaction, the conversion of HCO-1130was 25.4%, and the selectivity for HFC-143 was 7.4%.

A comparison between the results of Example 13 and the results ofExample 14 indicates that the conversion can be greatly increased byincreasing the pressure to 0.6 MPaG.

Example 15

Under the conditions in Example 14, 1% of O₂ relative to the total flowrate was entrained.

After 15 hours from the start of the reaction, the conversion ofHCO-1130 was 44.2%, and the selectivity for HFC-143 was 17.8%.

Example 16

HFC-143 was synthesized in the same manner as in Example 15, except thatthe reaction temperature was changed to 260° C.

After 2 hours from the start of the reaction, the conversion of HCO-1130was 54%, and the selectivity for HFC-143 was 17.5%.

Example 17

HFC-143 was synthesized in the same manner as in Example 15, except thatthe reaction temperature was changed to 280° C.

After 2 hours from the start of the reaction, the conversion of HCO-1130was 55.4%, and the selectivity for HFC-143 was 18.2%.

A comparison between the results of Example 14 and the results ofExamples 15 to 17 indicates that adding oxygen can increase not only theconversion, but also the selectivity for HFC-143.

The invention claimed is:
 1. A method for producing1,1,2-trifluoroethane (HFC-143), the method comprising contacting in agas phase at least one chlorine-containing compound selected from thegroup consisting of 1,1,2-trichloroethane (HCC-140),1,2-dichloro-1-fluoroethane (HCFC-141), 1,1-dichloro-2-fluoroethane(HCFC-141a), (E,Z)-1,2-dichloroethylene (HCO-1130 (E,Z)), and(E,Z)-1-chloro-2-fluoroethylene (HCFO-1131 (E,Z)) with hydrogen fluorideto perform one or more fluorination reactions, thereby obtaining areaction gas containing HFC-143, hydrogen chloride, and hydrogenfluoride, wherein the contact time W/Fo between the at least onechlorine-containing compound and the hydrogen fluoride is 0.1 to 100g·sec/cc in the one or more fluorination reactions.
 2. The productionmethod according to claim 1, wherein the one or more fluorinationreactions are performed under a pressure of 0 to 2 MPaG.
 3. Theproduction method according to claim 1, wherein the one or morefluorination reactions are performed in the presence of a catalyst. 4.The production method according to claim 3, wherein the catalyst is atleast partly a chromium-based catalyst.
 5. The production methodaccording to claim 1, wherein the one or more fluorination reactions areperformed at a temperature of 150 to 600° C.
 6. The production methodaccording to claim 1, wherein the molar ratio of the hydrogen fluorideto the at least one chlorine-containing compound in the one or morefluorination reactions is 20 or more.
 7. The production method accordingto claim 1, wherein the molar ratio of the hydrogen fluoride to the atleast one chlorine-containing compound in the one or more fluorinationreactions is over
 40. 8. A method for producing 1,2-difluoroethylene(HFO-1132), the method comprising producing 1,1,2-trifluoroethane(HFC-143) by the production method of claim 1, and subjecting the1,1,2-trifluoroethane (HFC-143) contained in the reaction gas obtainedby the production method of claim 1 to a dehydrofluorination reaction.9. A method for producing 1,1,2-trifluoroethane (HFC-143), the methodcomprising contacting in a liquid phase at least one chlorine-containingcompound selected from the group consisting of1,2-dichloro-1-fluoroethane (HCFC-141), 1,1-dichloro-2-fluoroethane(HCFC-141a), (E,Z)-1,2-dichloroethylene (HCO-1130 (E,Z)), and(E,Z)-1-chloro-2-fluoroethylene (HCFO-1131 (E,Z)) with hydrogen fluorideto perform one or more fluorination reactions, thereby obtaining areaction gas containing HFC-143, hydrogen chloride, and hydrogenfluoride, wherein the one or more fluorination reactions are performedin the presence of a catalyst, and the catalyst is at least partly anantimony-based catalyst.
 10. A method for producing 1,2-difluoroethylene(HFO-1132), the method comprising producing 1,1,2-trifluoroethane(HFC-143) by the production method of claim 9, and subjecting the1,1,2-trifluoroethane (HFC-143) contained in the reaction gas obtainedby the production method of claim 9 to a dehydrofluorination reaction.